Method for manufacturing segmented tracks



, Dec. 16, 1958 R. E. SAUSAMAN 2,364,154

METHOD FOR MANUFACTURING SEGMENTED TRACKS 2 Sheets-Sheet 2 Filed NOV. 26, 1954 I L- IHHHHHH J7 Illlll II\ Patented Dec. 16, 1958 METHOD FOR MANUFACTURING SEGMENTED TRACKS Robert E. Sausaman, Akron, B. F. Goodrich Company, ration of New York Ohio, assignor to The New York, N. Y., a corpo- This invention relates to the manufacture of tracks for track-laying vehicles, and is especially useful in the manufacture of tracks for this purpose characterized by an assemblage of individual track segments connected end-to-end, and in which each of the track segments includes one or more rubber-covered flexible tension bands to sustain the longitudinal tension in the tracks. Features of the invention may also be advantageously utilized in the manufacture of non-segmented tracks, viz., tracks which have an integral unitary structure throughout their length.

A particularly durable segmented track structure has been recently developed embodying a flexible rubbercovered tension band which is reinforced internally with a metal tension member composed of a plurality of flexible reinforcing members and a pair of anchor plates to which the ends of these members are secured. In these bands the reinforcing members are preferably stranded cables which are disposed lengthwise through the rubber body of the band in a common plane and the terminal ends of the cables at each end of the band are collectively secured' to a single anchor plate by swaging or otherwise deforming the plate against the cables. In order for the bands to operate properly it is important to construct the tension member of each band so that the tension loads to which the bands are subjected are equally distributed among the several cables. Prior to this invention, the manufacture of these bands has been prohibitively expensive because of the highly skillful workmanship required to make the metal tension members. The present invention provides a novel method for manufacturing these tension bands with acceptable precision and considerably faster than has been previously possible. The invention includes preferred apparatus useful in practicing the method.

According to this invention the improved method for making the tension members broadly involves deformably engaging a series of plates in spaced relation to a reinforcing member, and transversely severing the memberto divide it into segments each containing a plate secured to each end of the segment of the reinforcing 4 member. More specifically the preferred method involves providing a group of plates of strongmalleable metal, each about twice the desired width of an anchor plate, and each having several mutually parallel openings through the thickness of the plate from one edge to the opposite edge. A series of these plates are strung together by threading a group of cables through the corresponding openings of the plates. Each plate is then arranged on the cables so that it is spaced from those adjacent it for a distance equal to the desired length of a segment, and then each plate is swaged to constrict the openings against the cables. Thereafter each of the plates, is severed medially and transversely to the cables to form the tension members. The rubber body is subsequently vulcanized to such members. The preferred equipment .for practising the method includes means to regulate the Spacing intermediate theplates before they are swaged to 'the cables, a swaging die, and means to tension on the cables to maintain them straight and parallel during the step of swaging the plates.

The invention will be further described with reference to the accompanying drawings which illustrate a segmented track structure embodying bands with metal tension members of the type which may bermade advantageously by the method of this invention and which also show the apparatus and various steps in the procedure for making-these tension bands.

In the drawings:

Fig. l is a plan view showing the sprocket and bogieengaging side of portions of a segmented track formed with several segments coupled together; portions of the segments being broken away;

Fig. 2 is a plan view drawn on an enlarged scale showing the manner of coupling and end of a band of one segment to the corresponding band of an adjoining segment;

Fig. 3 and Fig. 4 are cross-sectional views taken on the lines 33 and 44 respectively of Fig. 2;

Fig. 5 is a perspective view of one of the plates with several cables threaded through it but before the plate is secured to the cables;

Fig. 6 is a plan view of suitable apparatus for spacing the plates along the cables and for swaging the plates into engagement with the cables;

Fig. 7 is a side elevation of the apparatus of Fig. 6; and

Fig. 8 shows the plate of Fig. 5 after it is swaged to the cables, and further illustrates the step of severing the plate.

Referring to the drawings, the track structure shown in Fig. 1 is formed by assembling together end-to-end several individual track segments such as the track segments A, B and C. The track segments include laterallyspaced flexible tension bands 10 which extend lengthwise of the segments and the ends of which are coupled to the ends of thecorresponding bands of adjoining segments. The structure of the tension bands generally resembles the tension bands described and claimed in the copending application Serial No. 386,796, filed October 19, 1953, of Daniel M. Lynch now Patent 2,803,504 granted October 20, 1957. Each tension band 10 is formed with a flexible rubber body 14, and a plurality of flexible metal wire stranded cables 16 extending lengthwise of the rubber body from an anchor plate 17 at one end of the band to another annular anchor plate 17 at the opposite end. The anchor plates 17 are disposed transversely to the cables at the ends of the band and each is swaged against its respective group of cable ends. The cables and the endwise anchor plates 17 compose an integral element of each band and this assembly is hereinafter referred to as the tension member of each band.

The track segments shown in Fig. 1 further incude a plurality of ground-engaging grousers 18 which are fastened transversely across the pair of bands 10 to lugs 19 which project laterally through the sides of the bands from cross-plates 20 which are embedded within the rubber body 14 of the bands at equally spaced intervals to provide driving engagement between the flexible cables 16 of the band and the grousers 18. On each grouser between the bands 10 there are upstanding guide members 21 flanked by driving lugs (not shown). The guides and lugs are engaged by the sprockets of the vehicle on which the tracks are mounted. This general arrangement of the grousers, cross plates, guides etc. is described in detail and claimed in U. S. Patent 2,494,066 to C. O. Slemmons.

The anchor plates 17 (see Fig. 4) are each flat metal bars which are slightly thicker than the diameter of the cables, and which are ly-spaced, parallel openings 25 extending sideways through provided with a plurality of lateralthe thickness of the plate from its forward edge 26 toward its rearward edge 27. The spacing of the openings 25 is equal to the lateral spacing between the cables so that theendsof the cables extend straight into/their respective openings 25 without being kinkedor deflected. The mouth of each of the openings25 at the forward edge 26 of the anchor plate is preferably belled or funnelshaped so that the cables may be flexed through a substantial angle relative to the anchor plate without being pinched or creased by the mouth of the openings. Each anchorplate'additionally is formed with upper and lower fiat faces 29 and 30, respectively, and areas of these faces as indicated by numeral 32 in Figs. 4 and 8 are swaged against all of the cable ends; assembled in the openings 25 to engage the anchor plates'to the cables.

The anchor plates 17 of two adjoining bands are coupled together as best shown in Figs. 3-4, by upper and lower coupling members 34 and 35 respectively. The anchor plates 17 are assembled with their'rearward edges 27 abutting at about the longitudinal center-lineof a grouser 18 which underlies the junction, and the rubber body 14 of each band terminates short of theanchor plates 17 in an end wall 36 leaving the upper and lower faces 29 and 30 of the anchor plates exposed to receive the coupling members 34 and 35. These latter members bridge or straddle the abutting anchor plates to enclose them, and through each of the corners of the coupling members there is a hole 38 which registers with a hole 39 (Fig. 8) through the anchor plates to receive a nut and bolt 40 or other suitable fastener to secure the coupling members tightly to the anchor plates. Each of the upper and lower coupling members has a layer of rubber 41 bonded to them of the same contour as the rubber bodies 14 of the tension bands and which abuts the end walls 36 of the rubber bodies to provide a continuous rubber surface across the junction of the bands.

In accordance with the present invention the metal tension member of each band 10 consisting of the several cables 16 and anchor plates 17 at the terminal ends of the cables is fabricated as an integral unit before the rubber body 14- with the cross-plates, etc., is molded around the cables. In making the tension member, the material from which the anchor plates are formed is initially provided in the form of flat generally rectangular plates 50 as shown in Fig. 5, and from each plate 50 two anchor plates 17 are ultimately made. The length and thickness of each plate 50 is equal to the required length and thickness of an anchor plate 17, but the width of each plate 50 is equal to twice the desired width of each anchor r plate as indicated by the dimension lines in Figs. and 8. The plates 50 are provided with several openings 25 which extend through the thickness of the plate for the full width of the plate toreceive the cables 16. The diameter of the openings 25 is preferably only slightly larger than the diameter of the cables to permit the cables to be inserted manually into their respective openings.

The first stage in the manufacture of the tension member is to thread a group of cables 16 in continuous lengths from their respective supply reels (not shown) through the corresponding openings 25 of several plates 5%. Thereafter the plates 50 are spaced along the cables at the particular distance desired for the length of the tension band, and then the areas 32 of the plates 50 are swaged inwardly to constrict the openings 25 about the cables.

The operation of spacing and swaging the plates may be advantageous performed with the equipment shown in Figs. 6 and 7. This equipment includes a base member 55 having a swaging die 58 located intermediate the ends of the base which is designed to receive a plate 50 with the cables threaded through the openings in the plate. At the left end of the base there is a jig 60 located a fixed distance from the die 58 and is designed to receive a-swaged plate 50 and thereby serve as a gauge to regua late the length of the cables between a swaged plate 50 in the jig and a plate 50 then in the die 58. At the opposite or right end of the base there is a device 62 to tension the portion of the cables extending from the jig 69 through the plate positioned in the die, and also there is a clamping member 64 to maintain the cables under tension as the plate 50 is swaged by the die.

The major elements of die 58 as shown in Figs. 6 and 7 consist of a lower die block 58-A upon which the lower surface of a plate 50 rests and an upper die block 58B which is slidable on vertical guide pins 66 toward and away from the lower block. Along the margins of the lower die 58A adjacent the sides of the base there are retaining members 68 equal in thickness to the plates 50. These retaining members 68 are fastened to the lower die 58-A and are adapted to closely abut the end edges 69 of the plate 50 to prevent the plate from elongating transversely to the cables when swaging pressure is applied by the die blocks. The retaining members 68 additionally include short inwardly directed portions 70 (Fig. 6) which extend around the corners of the plate 50 to prevent distortion of the dimensions of the corners of the plate by the swaging pressure of the dies. The full dimensional distortion of the plate 50 as a result of the swaging pressure is permitted to occur along the portions of the edges 26 of the plate intermediate the portions 70 of the re; straining members 68, and thus these edges 26 will. be distorted or bulged outwardly axially of the cables as indi: cated by the numeral 72 in Fig. 6. Distortion in these portions of the edges 26 is not objectionable since these edges are not engageable with other parts of the track structure in the subsequent assembly of the remaining parts of a track segment.

The plate-engaging faces of the lower and the upper die blocks 58-A and 58-13 are embossed with a series of ridges 75 which form indentations 32 in the upper and lower faces of the plate when the die is closed by a suitable press (not shown). In the type of die shown, the ridges 75 are disposed so that the resulting indentations 32 in the plate 50 extend transversely to the cables and the indentations 32 formed by the ridges 75 of the upperdie block are offset intermediate the corresponding indentations 32 formed by the ridges 75 of the lower die block. However, for the practice of this invention, the particular pattern in which the indentations are made may take a number of different forms.

The jig 66 at the left end of the base 55 includes a pair of upright members 77 rigidly secured to the base and interconnected near their upper ends by a cross bar 78. Each of the upright members 77 is provided with a rabbet 79 in its upper edge directed away from the die 58 The members 77 and 78 of the jig jointly support a plate 50 together with the cables to which it is swaged with two of the corners of the plate fitting into the rabbets 79 as best shown at the extreme left of Figs. 6 and 7. A horizontal adjusting screw 80 is threaded through each of the upright members 77 so that it communicates with the rabbet 79 and bears against the corners of a plate 50 in the jig to serve as a means for accurately adjusting the alignment and position of the plate 50 in the jig. The jig 60 is located on the base 55 so that distance from the corners of a plate 50 engaged with the rabbets 79 to the corners of the next adjacent plate 50 positioned in the die 58 is equal to the desired length for the cables in the tension member. Thus, by maintaining some tension on the cables from a plate 50 in the jig, the length of all of the cables betweenthe plate in the jig and the next succeeding plate then positioned in the die 58 will be equal to each other.

To apply tension to the cables, the tension device'62 at the right end of base 55 in Figs. 6 and 7 includes'a bar 84 disposed transversely above the base 55 with plates 85 rigidly fastened to each end of bar 84 and directed downwardly adjacent opposite sides of the base. These end plates are pivotally secured to the base by a transverse shaft 86 extending through and journalled in the base and to the ends of which the plates 85 are secured. One end of the shaft 86 projects laterally through the bracket at one side of the base and terminates in a hexagonal-shaped lug 87 which is engageable with a suitable wrench or the like to swing the bar 84 pivotally relative to thebase. The end plates 85 additionally extend upward from the cross bar 84 to support between them a shaft 89 upon which is rotatably mounted a series of clamping dogs 90. The several cables are arranged to extend between the bar 84 and the shaft 89 and each cable may be locked against the bar 84 by its respective dog 95. Each dog 90 as shown in Fig. 7 includes a handle 91 to rotate the dog about the shaft 89, and a lug portion 92 to engage the cable. Each dog 90 additionally has a flattened surface 93 so that when the dog is turned by the handle 95 to a position in which the flat surface 93 is parallel to the cables, there is a sufficient clearance to permit a plate 50 to be inserted therebetween and the cables to be moved freely on the bar 84. When the cables are threaded properly between the shaft 89 and the bar 84, the cables may be pulled taut manually so they are reasonably straight, or weights (not shown) may be hung on the cables to the right of the tensioning device 62 to straighten the cables. Then each of the dogs 90 is operated to frictionally engage the cables by pressing them against the bar 84. Then the operator with a wrench or the like can engage the hexagonal lug 87 and rotate the bar 84 (clockwise as viewed in Fig. 7) to exert the desired degree of tension on the portion of the cables extending from a plate 50 in the jig 60 through an unswaged plate 50 in the die 58.

The tension applied to the cables by turning the lug 87 is maintained by the clamping device 64 while a plate fitl in the die 58 is swaged to the cables. This device includes a transverse bar 94 rigidly secured to the base and having upright end members 95 supporting a shaft 96 upon which is rotatably mounted a series of clamping dogs 97 which are identical to the dogs 90 of the tensioning device 62. Thus when the cables are tensioned, the dogs 97 may be operated to lock the cables tightly against the bar 94 to maintain this tension. Relatively little tension is actually required to be exerted on the cables, the amount being suflicient to ensure that the residual curvature clue to the coiling of the cables in the supply reels is removed and that the cables are parallel to each other and that they do not sag intermediate the die 58 and the jig 60. Accordingly, the devices 62 and 64 may be aptly described as cable-straightening members.

To summarize the operation of the equipment shown in Figs. 6 and 7, a plate 50 which has been swaged against the cables is positioned in the jig 60 with two of its corners engaged within the rabbets 79 of the jig. Then the next succeeding anchor plate 58 is adjusted along the cables and positioned within the restraining members 68 of the lower die SS-A. Then the cables are tensioned by the tensioning device 62 which pulls the cables through the openings 25 of the plate 58 in the die 58 thus straightening the portion of the cables between the jig 60 and the die. Thereafter the dogs 97 of the clamping device 64- are locked against the cables to maintain them under tension, and then by means of a suitable power press or the like (not shown) the upper die 58-B is rammed against the plate 50 in the die 58A to form indentations 32 in the upper and lower faces of the plates and thus simultfiieously constrict all of the openings 25 of the plate against their respective cables with a single pres-.

sure stroke of the press.

After the plate 50 in the die 58 has been swaged to the cables, it in turn is moved forwardly to the jig 6t) and the foregoing operations are repeated until a number of plates 58 are secured to the cables at intervals determined by the distance between the jig 60 and the die 58. Then the holes 39 are formed (by equipment not 6 shown) in the corners of each plate 50. The position of theholes 39 may be located from the end edges of the plates which are maintained at accurate dimensions by the restraining members 68 of the die.

The concluding stage in the construction of the metal tension members is to sever the cables transversely into individual segments. This is accomplished by severing each of the plates 50 lengthwise with a saw 98 or other cutting device in a manner represented in Fig. 8 to divide each plate 50 into two anchor plates 17. In this operation each plate is divided along its longitudinal centerline 99, thereby severing the cables so that they terminate flush with the cut edges of the resulting anchor plates. The rubber body 14 is thereafter molded about each tension member to form the band, the anchor plates of which may be coupled together to form a joint as shown in Figs. 24. The cut edges of the plates 50 are obviously the rearward edges 27 of each anchor plate.

Each tension member is preferably dipped in a liquid solution of rubber which is then dried prior to molding the rubber body in order to augment the adhesion of the rubber to the metal parts. The cross plates 20 of the band and/or other articles are appropriately assembled with the tension member in the operation of molding the rubber body.

It is evident the foregoing steps of swaging the plates, severing the plates, and the operation of forming the holes 39 in the plates may be accomplished simultaneously by an appropriately designed die substituted for the die 58. The scope of the invention includes performing these operations in separate steps, or in a single operation. For making a non-segmented track, for example, an endless integral track, plates may be provided which are preferably narrower in width than the plates 50 illustrated but which are otherwise of the same design. Then a continuous cable may be threaded in a helical coil through the openings 25 of a series of such plates, and the plates spaced and swaged in the same manner as is shown in Figs. 6 and 7. In making this structure, the step of severing the plates after they are swaged to the cables is obviously omitted.

Variations in the structure and the procedure described may be made within the scope of the appended claims.

I claim:

1. The method of making a tension member for eventual use in a self-laying track which tension member includes a plurality of laterally-spaced flexible reinforcing cables and an anchor plate joined to the terminal ends of the cables at each end of the tension member, the method comprising providing a plurality of plates each with a plurality of openings extending therethrough, threading a flexible cable through each of the corresponding openings of said plates from one plate to another, arranging the plates in spaced relation to each other lengthwise of the cables so that between opposing edges of each two anchor plates the cable portions extending between such two plates are all of equal length, deforming each plate to constrict its respective openings about the portion of each cable extending through each opening, and then transversely severing assembly adjacent the anchor plates to divide the cables into discrete segments each containing a group of cables with an anchor plate extending transverse to the end of each cable at each end of the segment to which anchor plates the cable ends are collectively secured.

2. The method of making a tension member for eventual use in a self-laying track which tension member includes a plurality of laterally-spaced flexible wire stranded cables and a single anchor plate at each end of the tension member to which the terminal ends of the cables are collectively secured, the method comprising providing a plurality of flat metal plates each equal in length and in thickness but having twice the width ultimately desired for each anchor plate and each of said plates having openings extending edgewise through the thickness of the plate parallel to and intermediate plane upper and lower faces ofthe plate and transverse to the length of the plate, threading a flexible cable through each of the corresponding openings in several of the plates so that each cable extends continuously from one plate to another, swaging areas of said upper and lower faces of each plate to constrict said openings about the portions of each cable extending therethrough, and severing each plate medially of its width thereby also severing the cables to which the plate is swaged to divide the plate into anchor plates secured to the severed ends of the cables.

3. The method of making a tension member for eventual use in a self-laying track which tension member includes a plurality of laterally-spaced flexible wire stranded cables and an anchor plate joined to the terminal ends of the cables at each end of the tension member, the method comprising providing a pair of plates each with mutually parallel openings extending through the plates, threading a series of continuous cables through the corresponding openings of said plates so that the cables extend continuously from one plate to the other, deforming one of said plates to constrict its openings about the portions of the cables the openings respectively embrace, spacing the other of said plates a predetermined distance lengthwise on the cables from said deformed plate, tensioning the cables between said deformed plate and said other plate, deforming said other plate to constrict its openings about the portions of the cables the openings respectively embrace, and severing each of said plates medially in a direction transverse to the cables thereby also severing the cables.

4. The method of making a tension member for a segrriented'track which includes a pair of spaced apart end anchor plates and a plurality of flexible reinforcing members of equal length extending from one anchor plate to the other, which method comprises providing a series of plates each having a group of openings extending through the thickness of the plate from one edge to an opposing edge, threading reinforcing members through corresponding openings in'the plates from plate to plate so that the plates are strung onto the reinforcing members like beads on a necklace, spacing the plates lengthwise from each other on said members so that between opposing edges of two spaced plates the portions of the reinforcing members between such two plates are all of equal length, deforming each said plate to constrict its respective openings about the portion of the reinforcing member therethrough, and severing each plate and the reinforcing members extending through its respective openings in a direction transverse to the length of the reinforcing members to divide the assembly into said tension members.

References Cited in the file of this patent UNITED STATES PATENTS 1,711,832 Cooper May 7, 1929 1,906,782 Zapf May 2, 1933 2,092,830 Brickman Sept. 14, 1937 2,107,490 Mayne Feb. 8, 1938 2,109,837 Davis Mar. 1, 1938 2,225,739 Elliott Dec. 24, 1940 2,340,448 Andren Feb. 1, 1944 2,386,119 Jack Oct. 2, 1945 2,430,986 Kline Nov. 18, 1947 2,464,432 Brickman Mar. 15, 1949 2,494,066 Slemmons Jan. 10, 1950 2,803,504 Lynch Aug. 20, 1957 

